For deburring and polishing of moldings, pressed products, and machined products of metals, a polishing tool in which the base ends of linear grinding members are bundled with a grinding member holder so as to form a brush-shape is employed. Patent Literature 1 describes a polishing tool unit (polisher brush) in which a polishing tool is held by a tool holder including a shank serving as an attachment part to a processing machine. The tool holder includes a sleeve coaxial with the shank. The polishing tool is held by the tool holder in a state that a grinding member holder is inserted into the sleeve, and the free ends of linear grinding members protrude from the tip opening of the sleeve. The grinding member holder is movable inside the sleeve in the axial direction, and adjustment of the protruding amount of the linear grinding members from the sleeve is made by moving the grinding member holder in the axial direction.
Here, using a fixing screw, the grinding member holder is fixed to a desired position in the sleeve in the axial direction. That is, an opening is formed in the circumferential wall of the sleeve over a predetermined range in the axial direction, and a threaded hole is formed in the grinding member holder so as to penetrate in a direction perpendicular to the axial direction. A fixing screw is tightened from the opening side so that the tip part of the fixing screw comes into contact with the inner circumferential surface of the circumferential wall part, whereby the grinding member holder is pressed against the inner circumferential surface of the circumferential wall, and fixed.